#include<iostream>
#include<string>
using namespace std;
class myVector
{
	private:
		double x;
		double y;
	public:
		myVector(double x=0,double y=0)
		{
			this->x=x;
			this->y=y;
		}
		myVector operator ++ (int i)
		{
			myVector res;
			res.x=x+x;
			res.y=y+y;
			x+=x;
			y+=y;
			return res;
		}
		myVector operator + (myVector a)
		{
			myVector res;
			res.x=a.x+x;
			res.y=a.y+y;
			return res;
		}
		myVector operator - (myVector a)
		{
			myVector res;
			res.x=a.x-x;
			res.y=a.y-y;
			return res;
		}
		void show()
		{
			cout<<"x y:"<<x<<" "<<y<<endl;
		}
};
int main()
{
	myVector a(3,9),b(7,6);
	a++;
	a.show();
	a=a+b;
	a.show();
	return 0;
}
